18TB hard drives made possible using table salt

Hard drive storage continues to increase at a steady rate, but just how long can we keep squeezing more data on to those platters? TDK has managed to ensure that the density keeps rising for a few more generations with its HAMR head innovation, but that may have already been rendered redundant through another discovery by a Dr Joel Yang at the Institute of Materials Research and Engineering (IMRE).

Existing hard drives max out at 3TB at the moment. TDK’s HAMR promises to take that to 6TB, but Dr Yang has found a way to increase the data density of a drive to 3.3 Terabit/inch2, effectively meaning 18TB hard drives are possible.

What may surprise you is the key to this massive increase in data storage density. Dr Yang used table salt, or more specifically, sodium chloride.

Data stored on a hard drive is done so using nanoscopic magnetic grains. Typically, several of these grains (a cluster), each measuring around 7nm, are used to store one bit of information. Therefore, if you can pack them more densely together, you get more storage in the same space.

By adding sodium chloride to the mix, it has been possible to get a single 10nm grain storing one bit. Replacing several 7nm grains with one 10nm saves a lot of space and therefore ups the storage density considerably.

The good news is the use of sodium chloride can be added to existing lithography processes, suggesting it won’t take too long to get this up and running for commercial drives. So far a 1.9 Terabit/inch2 storage solution has been shown to work, but that will increase to 3.3 Terabit/inch2, and then further research and development is aiming to achieve 10 Terabit/inch2 in the future.

For us as consumers, it means the hard drive still has quite a few years of storage bumps still to come, and a greater challenge for SSDs trying to catch up with the amount of storage on offer. This also bodes well for data centers who need to cater for a never-ending storage need as more cloud services go online.